Production of diolefinic hydrocarbons



Patented Apr. 4, 1944 UNITED STATES PATENT OFFICE PRODUCTION OF DIOLEFINIC HYDROCARBONS Vladimir N. Ipatieif, Chicago, Ill., assignor to Universal Oil Products Company, Chicago, 111., a corporation of Delaware No Drawing. Application April 12, 1941, Serial No. 388,269

4 Claims.

This invention relates to the conversion of isopropyl alcohol into diolefinic hydrocarbons. More specifically it is concerned with a process involving the use of a particular catalyst and specific conditions of operation whereby isopropyl 5, The different forms of magnesia which. may alcohol can be converted efiiciently into hexbe employed as catalysts for the present process adienes. are not necessarily equivalent in their action and In one specific embodiment the present inventhe operating conditions employed depend upon tion comprises a proces for producing a dithe activity of the catalyst utilized. olefinic hydrocarbon from isopropyl alcohol The following specific examples are introduced which comprises subjecting said alcohol to conto show results obtained in the operation of the tact with a magnesium oxide catalyst at a term process, although these data are not presented perature of from about 400 to about 500 C. with the intention of unduly limiting the broad This invention relates to the production of discope of the invention. olefin hydrocarbons from isopropyl alcohol by Example I treating this alcohol with magnesium oxide catalyst at a temperature of from about 400 to During a DeYiOd 0f hours, 242 Volumes of about 500 C. and preferably within the approxiisopr alcohol Was p sed at 465 C. over mate limits of about 400 and 450 0. The opervolumes of magnesium Oxide Obtained by P ating pressure is substantially atmospheric or 20 (imitation in e f of e y ide. D rin subatmospheric and t hourly charging rate f this treatment 40,000 volume of gas was obtained alcohol is generally up to about 4 times the voland a qu d p d t w s formed ntain we of th catalyst. By t proces of t volumes of unsaturated liquid hydrocarbons boilvention isopropyl alcohol is converted into a dimg between about and The e olefinic hydrocarbon, nameqy a hexadiene, 25 verted isopropyl alcohol was suitable for recyclln taining twice the number of carbon atoms per to further Catalytic treatmentl l as present in Said alcohoL The unsaturated hydrocarbons thus obtained While the reactions involved in the process of in a yield of about 15% per P based upon the this invention are not understood clearly or comisopropyl c l charged, upon catalytic hypletely, they probably comprise essentially a drogenetion feund Combine cooperation of dehydration, condensation, and leclllal p po t ons of hydrogen to yield lsodehydrogenation reactions producing one or more hexane, and were thus Shown to be dlelefimetypes of diolefini hydrocarbons The 40,000 volumes of gaseous products formed A preferred catalyst utilizable in the process Contained about 94% of hydrogen as indicated by of this invention is obtained by precipitating the following analysis: olefins 41%? Oxygen magnesium hydroxide or magnesium carbonate 03%? hydrogen, 941%; Pereffins, and by the addition of a solution of a base or of a tween The perefihlns Present 111 the gas water-soluble carbonate to an aqueous solution Probably eonsleted of e mlXtuTe of methane and of a magnesium alt followed ashing to -e ethane Since the gas analysis Showed a carbon move water-soluble impurities from the preindex of for the Pereffins present cipitated material, then drying and heating the Example [I precipitate to drive on water or carbon dioxide and form substantially pure magnesium oxide. Dunne per 10d of 10 hours 570v1ume5 of Magnesium oxide, otherwise known as isopropyl alcohol was passed at 470 C over 25 nesia, obtained from either of the above indicated volumes of the magnesla catalys? ufdlcated in sources, may be employed in the form of a fixed Example The volllmes of hqmd products bed through which the reaction mixture is passed, obta'med miter Washmg Wlth wefter to remove or it may be utilized as powder in a substantiall converted isopropyl alcohol, yielded 67 volumes fluid t of operation The magnesia catalyst of a hydrocarbon layer consisting essentially of may b formed i t particles by a number f diolefinic hydrocarbons. The total yield of dimethods such as pelleting into bodies of regular Olefinic hydrocarbons Was about f the shape and size or pressing the powdered magnesia theoretifial based p the q y p py t form a k which is h d and screened alcohol passed over the catalyst. More than onet i granules f irregular shape d size M half of the diolefin hydrocarbon fraction formed terial which has been made plastic by addition in this ru boi ed from about to about C.

Other runs made in the presence of commercial magnesium oxide gave lower yields of dioleflnic hydrocarbons. Further, it was found that the diolefin yield per pass was increased by decreasing the charging rate as measured by the liquid space velocity of charge.

The nature of the present invention and particularly its commercial value are evident from the preceding specification and examples, al-

though neither section is intended to unduly limit its generally broad scope.

I claim as my invention:

1. A process for producing a diolefinic hydrocarbon from isopropyl alcohol which comprises subjecting said alcohol to contact with a catalyst consisting essentially of magnesium oxide at a temperature above 400 and below 500 C.

carbon from isopropyl alcohol which comprises subjecting said alcohol at a temperature above 400 and below 500 C. toccntact with a catalyst consisting essentially of magnesium oxide formed by treating a water-soluble magnesium salt with a base to form a precipitate of magnesium hydroxide, Washing said precipitate to substantially remove water soluble impurities, drying and calcining the washed precipitate to form substantially pure magnesium oxide.

4. A process for producing a hexadiene from isopropyl alcohol which comprises subjecting said alcohol at a temperature above 400 and below 500 C. under a pressure of from subatmospheric to substantially atmospheric to contact with a catalyst consisting essentially of magnesium oxide formed by treating a water-soluble 2. A process for producing a diolefinic hydrocarbon from isopropyl alcohol which comprises subjecting said alcohol to contact with a catalyst consisting essentially of magnesium oxide at a temperature above 400 and below 500 C. under a pressure of from subatmospheric to substantially atmospheric.

3. A process for producing a diolefinic hydromagnesium salt with a base to form a precipitate of, magnesium hydroxide, washing said pre cipitate to substantially remove water-soluble impurities, drying and calcining the washed precipitate to form substantially pure magnesium oxide.

VLADIMIR N. IPA'I'IEFF. 

